Formation of high purity Si nanofiber from metallurgical grade Si by molten salt electrorefining

► High-purity Si (99.98 wt%) was deposited from MG-Si by a electrorefining process. ► We purify metallurgical grade Si from solutions of K2SiF6 in fluoride melts. ► We examine polarization behavior according to concentration of K2SiF6 and current. ► Nodular or fibrous deposits were formed according to processing parameters.